NRP Spring 2023. Nate Franco: Are fats to blame?

In 1980 the USDA and HHS released new dietary guidelines regarding recommendations for the public’s consumption of different types of food. Included in these guidelines were instructions that consumers should “maintain an ideal weight” by limiting their dietary fat intake so that it would make up less than 30% of their caloric intake. The recommendations for starches and carbohydrates, on the other hand, encouraged their consumption in the place of fat, noting that “if you limit your fat intake, you should increase your calories from carbohydrates to supply your body’s energy needs”. The Food and Dietary Guidelines for Americans is not just some ideal goal that is set for the country, it has widespread social and practical implications. For example, they can widely affect the supply of food in the United States by altering everything from school lunch programs to federal food assistance programs. The grasp they have on the food industry means that the health of millions of Americans is also affected by them. The intensions of the 1980 edition were to help to curb the public health issues that were obesity, diabetes, and heart disease by emphasizing the reduction of fats, specifically saturated fats and cholesterol. While the guidelines may have arisen from the fact that fats contain more calories per gram that carbohydrates, they have had many consequences in the more than 30 years that they have stood.

The dietary guidelines precipitated the replacement of fats with carbohydrates and starches in the food that was being produced and consumed in the United States. The cause of this shift could be attributed to many things including government influence on food production or the response of consumers and media which created a stigma around the consumption of fats. Either way, the effect was real and evident. Products in the past three decades have increasingly cut fat content out of them and have compensated for taste by increasing sugar levels in many products. Instead of helping solve the issues of obesity and diabetes, guidelines and misunderstood research framed fats and cholesterol as inherently bad. This negative connotation persists today. The intake of sugars and carbs in the American diet have had a positive correlation to increased rates of diabetes, weight gain, and heart disease. Amazingly, not until they released their 2015 guidelines did the USDA and HHS change their stance and remove the limit on total dietary fat intake, leaving 30+ years for misunderstood science to take hold in American society.

Whether the issue of dietary fat intake was the result of “bad science” or the faulty application of the science to public policy is beside the point. Fats and cholesterol are essential to the diets of all people. Of course, all fats are not equal. Americans consume too much saturated fat in our diet from animals and dairy. These get converted to LDL, a bad form of cholesterol that can lead to buildups of plaques in the arteries and cause cardiovascular disease. On the other hand, consuming more unsaturated fats in things such as plant oils and fish helps to create a good form of cholesterol called HDL. HDL helps to break down LDL and is also important for brain health. Cholesterol in the brain helps to surround and insulate neurons in myelin, allowing the brain to send and receive signals properly. Studies have even shown that people who stick to a diet that is higher in unsaturated than saturated fats have lower risk of Alzheimer’s disease. It is important to balance your diet with the right fats, not limit them entirely.

There have been many more obvious instances in history where science has missed the mark, but even small misinterpretations or lack of data can have large effects on populations. Science isn’t static, it is always changing with new developments, but it is important to minimize errors with solid research and careful interpretation.

Sources

Dietary Guidelines for Americans, 1980th ed., USDA, 1980.

“Know the Facts About Fats.” Harvard Health, 19 Apr. 2021, https://www.health.harvard.edu/staying-healthy/know-the-facts-about-fats.

Mozaffarian D, Ludwig DS. The 2015 US Dietary Guidelines: Lifting the Ban on Total Dietary Fat. JAMA. 2015 Jun 23-30;313(24):2421-2. Doi: 10.1001/jama.2015.5941.